Drafting instrument



June 4, 1963 G. E. FORCE DRAFTING INSTRUMENT 2 Sheets-Sheet 1 Filed May 25, 1960 INVENTOR. GERALD E. FORCE 9" ATTORNEYS I40 BY June 4, 1963 G. E. FORCE DRAFTING INSTRUMENT 2 Sheets-Sheet 2 Filed May 25, 1960 FIGS FIGB

lF v i INVENTOR. GERALD E.FORCE ATTORNEYS Fl as BY United States Patent 3,091,864 DRAFTING INSTRUMENT Gerald E. Force, 1458 Columbia Road NW., Washington, D.C. Filed May 25, 1960, Ser. No. 31,662 6 Claims. (CI. 33-76) This invention relates to a drafting instrument and more particularly to a rollable straight edge for horizontal lining within which is enclosed a second straight edge pivotable to an extended perpendicular position and rollable along the first straight edge for vertical lining.

Prior art structures which contemplate means for effecting horizontal lining as well as vertical lining are characterized by the fact that such devices have heretofor been cumbersome and of such construction as to make it difiicult to manipulate the device. For example, the vertical liner is not easily' so constructed and arranged as to permit its movement to an outofthe-way position when it is not used. For this reason, it has heretofor been considered impractical to provide means by which vertical lining may be readily achieved since the dis advantages attendant upon the addition of such means will usually outweigh the advantages thereof.

Accordingly, it is a primary object of the present invention to provide a straight edge combined with a vertical liner both of which are easily movable on wheels which roll along fixed tracks.

Another object of the invention is to provide an improved drafting instrument of the indicated character in which the wheels and track construction are flat and thin and occupy little space being hardly thicker than a conventional straight edge.

It is a further object of the invention to provide an improved drafting instrument of the indicated character in which means are provided for locking the vertical liner in both its covered nonusable and extended usable positions, the latching means in the latter instance holding the liner perpendicular to the straight edge during rolling movements of the liner to facilitate the drawing of parallel vertical lines anywhere across the face of illustration board on the drafting table.

Still another object of the invention is to provide an improved drafting instrument of the indicated character which is readily usable to draw horizontal and vertical lines on illustration board placed on any part of a drafting table.

A still further object of the invention is to provide, in an instrument of the described character, a straight edge for ruling vertical lines which is shiftable out of the way when not required and lockable in a covered position.

Yet another object of the invention is to provide an improved drafting instrument of the indicated character in which is incorporated means for elevating the horizontal straight edge above the drafting table to accommodate very thick illustration board, such means including a pinrality of hinges which also permit the swinging of the horizontal straight edge, together with the vertical straight edge enclosed therein, to a position away from the illus tration board so that parts of the drafting work may be accomplished manually without the use of the instrument.

Another object of the invention is to provide an improved drafting instrument of the described character in which the horizontal straight edge and its mounting plate are formed of thin strip material cut out and folded to yield inexpensive but strong constructions which provide rail support to wheeled carriage assemblies for rolling movement of the straight edges.

Still another object of the invention is to provide an improved drafting instrument of the described character in which the folded construction covers and protects the wheeled carriage mechanisms for both straight edges.

A still further object of the invention is to provide an improved drafting instrument of the indicated character in which the vertical liner is removable from the straight edge for cleaning purposes.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout the several figures and in which:

FIG. 1 is a perspective view of a drafting instrument, in accordance with a preferred embodiment of the invention, shown aflixed to a drafting table with the vertical liner in extended work position;

FIG. 2 is a plan view of the instrument with parts broken away to reveal details of construction of the wheeled carriages which support the horizontal and vertical straight edges;

FIG. 3 is a side elevational View partially in section of the wheeled carriages which support the horizontal and vertical liners;

FIG. 4 is a fragmentary elevation partly in section showing the hinge construction of the horizontal straight edge when the straight edge is applied to unduly thick i1- lustration board;

FIG. 5 is a fragmentary plan view of the instrument showing the vertical liner positioned within the horizontal straight edge and with parts broken away to reveal the construction and arrangement of the vertical liner carriage elements;

FIG. 6 is a fragmentary exploded View showing the vertical liner and its supporting carriage structure;

FIG. 7 is a fragmentary perspective view showing de tails of the latching elements;

FIG. 8 is a fragmentary side elevational view showing the fixed support for the horizontal straight edge with parts broken away to reveal details of construction of the straight edge carriage, and

FIG. 9 is a sectional view of FIG. 8.

Referring now more particularly to the drawings, there is shown in FIG. 1 a drafting instrument according to the invention afiixed to a drafting table 10. The instrument comprises a straight which is rollably secured to a fixed T portion bearing the general reference numeral 14, and a second straight edge 16 which is rollably secured to the first straight edge. As will be described hereinafter, the ruler 16 is also pivoted to straight edge 12 so that it may be turned from an enclosed nonuse position, shown in FIG. 5, to a work position perpendicular to the straight edge 12, as shown in FIG. 1.

The straight edge 12, as well as other parts of the instrument, may be fabricated of metal, plastic or other suitable material. For purposes of economical construction, it is desirable to utilize a flat rectangular strip of thin metal in one half of which are punched out or stamped a longitudinal slot 18 and two parallel slots 20 and 22. The inner edge of each slot 2i and 2.2 is pressed inwardly to form an angular or semicircular flange or rail 24, as shown best in FIG. 6. The rectangular stamping 12 is then folded approximately about its center line to provide closely spaced parallel upper and lower sides 26 and 28, the slots 18, 2d and 22 falling in the upper side 26. The folded stamping 12 presents an edge 30 for ruling horizontal lines which preferably, although not necessarily, protrudes slightly beyond the upper side 2-6. The lower side 28 of the folded member 12 is attached at one end to the horizontal flange 32 of a vertically extaken along the line 9-9 edge generally indicated at 12' tending support 34. A hinge preferably having a plurality of parallel hinge axes such as 36, 37 and 38 may be used to attach the straight edge 12 to its vertical support 34. Q I

The fixed T portion 14 of the drafting instrument is, like the straight edge 12, also preferably formed as a metal stamping with some difierences in construction. Member 14 comprises a horizontally extending cover portion 40 and a vertically extending side 42 having end flanges 44 which are fixedly secured to an edge of the drafting table 113 by means of screws 46 or other suitable fasteners. The side 42 is centrally and longitudinally slotted at 48. The lower edge of side 42 is bent inwardly to provide a lower rail -0. A second and upper rail 56 is formed by the inbent edge of a slot 52 formed in the corner juncture of sides 40 and 42. The rails 59 correspond in function to rails 24 of the straight edge 12, as does slot 48 to slot 18 and slot 52 to slot 22 as will more clearly appear hereinafter.

The vertical straight edge or liner 16 is preferably marked with the indicia 54 of a length measurement scale. For pivotally and reliably securing the liner 16 to the straight edge 12, there is provided at the inner end of the liner an enlarged flat portion 56 to the center of which is affixed, in any suitable way, a cylindrical pivot stud 58 having a diametrical slot 6% in its upper edge, see FIG. 6. The slot 611 desirably aligns with slot 13 in the cover portion of straight edge 12 when the liner 16 is assembled at right angle thereto. A' pair of latching detents 62 and 64, spaced apart at a predetermined angular distance, are pressed upwardly from portion 56 at the ends of an arcuate slot 66.

Upon the end portion 56 of liner 16 is assembled a wheeled carriage or truck generally referenced 68. The carriage comprises a rectangular fiat plate 70 having a central opening 72 which pivotally receives the liner stud 58. Surrounding the opening 72 is a semicircular slot 74 which slidingly receives the latching detents 62 and 64 of the liner 16. At each end of the slot 74 is formed a stop tongue 76 pressed upwardly and then inwardly to form a latch flange 78 substantially parallel to the plate 70. The tongues 76 limit the pivotal movement of liner 16 to 90 degrees upon engagement with the detents 62 and 64 which are arranged 90 degrees apart. When the liner 16 is rotated to either its covered or exposed, work position, the tongue flanges 78 resiliently and frictionally engage the upper surface of detent 64 or 62, respectively, as clearly shown in FIG. 7, and hold the liner in such position until suflicient force is manually applied to overcome the latch friction and rotate the liner.

A pair of wheels 3% are rotatably secured to diagonally opposite corners of plate 70 with the plane of the wheels parallel to that of the plate. One means for such securement is to weld, solder or otherwise affix a spacer disc 82 flat against plate 70. The disc 82 beats a stub axle 84 on which rotates the wheel 8i) secured thereto by a cotter pin, not shown, or by other suitable means. The plate 70 is also notched at one edge to provide upturned abutrnents 86 and 88. Surrounding the pivot stud '58 is a wire coil spring 9%) which rests on'plate 7t and has distendiug ends 92 and 94.

' Seated on spring 96 is a flat strip 96 centrally apertured at 93 to receive the stud 58 and having a pair of wheels 1% rotatably secured to the ends thereof with the plane of the wheels parallel to the plane of the strip 96. The strip 96 is formed with a notch, one edge of which is downturned at 162. The distended ends 92, 94 of the spring are squeezed between abutments 38 and 1432, as best seen in FIG. 5, when the strip 26 and plate 71) are assembled to form the wheeled carriage 68. The spring 90 therefore urges the strip 96 to turn in a clockwise direction until stopped by engagement of the notch abutment 86 with the strip. Thus the wheels 1111? are urged against and resiliently held in engagement with the rails 24. To secure the wheels and carriage 68 between the rails, each wheel 81 and 1% is peripherally grooved as indicated at 1114 to seatthe edges of the rails.

Before completing assembly of the wheeled carriage 68 to the straight edge 12', a spacer washer 166 is dropped about stud SS and a spacer disc 108 is placed over the stud end. The underside of disc 108 is placed integral diametric rib 1113 which fits into slot 60 of the stud for turning the latter. An integral stub shaft 112 projects upwardly from disc 1198 and rides in slot 18 of the upper face 26 of the straight edge. When the wheeled carriage 68 and its described auxiliary parts have been assembled to the liner 16 with the wheels 160 urged into engagement with the rails 24, a manipulating knob 114 is assembled on stub shaft 112 outside the upper straight edge face 26 and keyed thereto by means of a key 116.

The vertical support 34 is provided with wheels for cooperation with the rails to act as a carriage for the horizontal straight edge 12 in a fashion quite similar to the arrangement of carriage 68 but simplified because of the omission of parts required to pivot liner 16 between its two positions. Referring more particularly to FIGS. 8 and 9, it will be apparent that the rectangular vertical support plate 34 is provided with a central stud 120 whose threaded outer end passes through and rides in slot 48 of the fixed T portion 14. A pair of diametrically opposed wheels 122 are rotatably affixed to the plate 34 to rotate in a plane parallel thereto and in a manner similar to that previously described for wheels 80. Another pair of wheels 124 are likewise carried at the ends of an arm 126, similar to strip 96, and pivoted with respect to the stud 120. The plate 34 has an inturned abutment flange 127 and arm 126 has another abutment 128.

A coil spring 130, similar to spring 90, has its distended ends squeezed between the abutments 127 and 128 and surrounds the stud 120 to turn the arm 126 clockwise as viewed in FIG. 8. This presses the wheels 124 into engagement with the rails 51) whose edges ride in peripheral grooves 132 formed in each of the wheels 122 and 124. During assembly of the wheels 122, 124, arm 126 and associated parts to the rails 50, a spacer collar 134 is utilized to surround the stud 120. A Belleville washer 136 is dropped over stud 120 between collar 134 and plate 42. When a nut 138 is screwed on stud 120 outside of plate 42, the conical spring washer 136 is squeezed to lock the vertical plate 34 and its assembled wheels and associated elements in a fixed position.

To utilize the described instrument, it will be apparent that the draftsman need only turn knob 138 slightly to lessen the pressure on the Belleville washer 136 and tree the straight edge 12 for rolling movement supported by the vertical plate 34 and its wheels 122 and 124 on the rails 50. Thus freed, the straight edge may be easily shifted along the fixed support 14 within the limits permitted by slot 4-8. Thus the edge 30 of member 12 may be used for horizontal lining anywhere on the illusrt-ration board mounted on the drafting table 10. When the draftsrnan desires to fix the location of the straight edge 12, it is merely necessary to tighten knob 138.

To utilize the vertical liner 16, the d-raftsman merely turns knob 114 with suflicient pressure to over-come the resilient latching friction of the detent tongue 78 to disengage the latch 64 and rotate the released liner 16 from its enclose-d position of FIG. 5 to its extended Work position of FIGS. 1 and 2. By pushing knob 114 along slot 18, the vertical liner may be shifted to any desired position along the straight edge 12. The straight edge 12 is maintained perpendicular to the support 14 and the edge of the drafting table to which it is affixed throughout all movements of the straight edge by reason of the fixed relation of wheels 122 to plate 34 and the spring pressure of wheels 124 against rails 56. Similarly, the carriage 63, during its movements, is maintained in the same relative position to rails 24. Since the vertical liner 16 is pivotable between two fixed positions, one parallel to the longitudinal center of the carriage plate 7 t1 and the other perpendicular thereto, as determined by the arrangement of the latching tongues 78 and their stop walls 76, the liner 16 when in its work position will always be perpendicular to the straight edge 12.

During use of the described instrument, the horizontal flange 40 acts as a cover and prevents entrance of any substantial amount of dirt, dust, erasings and the like into the fixed portion 14 that would tend to prevent free rolling of the straight edge carriage along rails 50. While it is possible for such materials to enter into the straight edge through the opening between the folded sides 26, 28 and through slots 18, 20 and 22, the carriage 68 and attached liner 16 may be easily removed for cleaning by sliding out through the end of the straight edge 12 if the slot 18 is extended to the edge.

The triple hinge construction of the straight edge enables the latter to lie flat even on very thick illustration board as clearly shown in FIG. 4. Also the plurality of hinges enables the straight edge to be swung 180 to extend away from the illustration board to allow free access for manual drawing operations. The flat folded construction and use of flat carriages with wheels lying parallel thereto is economical to make as well as economical of space.

Although a certain specific embodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

What is claimed is:

1. A drafting instrument comprising a mounting plate for fixed securement to an edge of a drafting table, said mounting plate having a pair of longitudinal inwardly bent flanges forming parallel rails, a carriage having wheels at its corners engaging said rails, a straight edge perpendicular to the rails of said mounting plate, said straight edge being formed of a flat sheet folded to provide closely spaced parallel walls open at one side, means for securing said straight edge to said carriage on the mounting plate for movement along the mounting plate rails, a vertical liner having one end positioned between the parallel Walls of said straight edge, a pivot stud at said end of the vertical liner and a pair of detents spaced 90 apart in an arc about said pivot stud, a second cartriage having a central opening receiving said pivot stud and positioned within the straight edge between the parallel sides thereof, said second carriage having a semicircular slot ending in bent terminal flanges for wedging engagement with said pair of detents, wheels at the corners of said second carriage, one of said parallel walls of the straight edge having a pair of longitudinal parallel rails formed by flanges and bent inwardly to extend into the space between the walls of the straight edge, said wheels of the second carriage engaging the straight edge rails, and means for securing said pivot stud of the vertical liner assembled in rotational engagement with said second carriage whereby said liner is movable from a covered position seated between the walls of and within said straight edge to an extended work position perpendicular thereto, the movements between said positions being limited by engagement of said detents on the liner with said terminal flanges on the second carriage.

2. A drafting instrument comprising a mounting plate for fixed securement to an edge of a drafting table, said mounting plate having a pair of longitudinal inwardly bent flanges forming parallel rails, a fiat plate carriage having disc wheels at its corners parallel to the plane of the carriage and each wheel having a peripheral groove engaged in one of said rails, a straight edge perpendicular to the rails of said mounting plate, said straight edge being formed of a flat sheet folded to provide closely spaced parallel walls open at one side,

means for securing said straight edge to said carriage on the mounting plate for movement along the mounting plate rails, a vertical liner having one end positioned between the parallel walls of said straight edge, a pivot stud at said end of the vertical liner and a pair of detents spaced apart in an are about said pivot stud, a second flat plate carriage having a central opening receiving said pivot stud and positioned within the straight edge between the parallel sides thereof, said second carriage having a semicircular slot ending in bent terminal flanges for wedging engagement with said pair of detents, disc wheels at the corners of said second carriage having peripheral grooves, one of said parallel walls of the straight edge having a pair of longitudinal parallel rails formed by flanges and bent inwardly to extend into the space between the walls of the straight edge, said peripheral grooves of the Wheels of the second carriage engaging the straight edge rails, and means for securing said pivot stud of the vertical liner assembled in rotational engagement with said second carriage whereby said liner is movable from a covered position seated between the Walls of and within said straight edge to an extended work position perpendicular thereto, the movements between said positions being limited by engagement of said detents on the liner with said terminal flanges on the second carriage.

3. A drafting instrument according to claim 2, wherein said means for securing the straight edge to said mounting plate includes a plurality of freely movable hinges in spaced parallel relation whereby said straight edge will lie flat and parallel to the drafting table upon unusually thick illustration boards and said straight edge may be turned upon said hinges to lie in a direction away from the illustration board on the table when not required.

4. A drafting instrument according to claim 2, wherein at least one of said wheels on each of said first and second carriages is resiliently urged into contact with the associated rail.

5. A drafting instrument according to claim 2, wherein said second carriage includes a raised abutment, a pair of said wheels for said second carriage being rotatably supported at the ends of a pivotable member having a central recess enclosing said pivot stud, said member being diagonally disposed with respect to said carriage and having a detent formed at one edge, a coil spring surrounding said pivot stud and having straight end portions, one of said end portions engaging the said carriage abutment and the other end portion engaging said detent on the diagonal member whereby to turn the diagonal member and resiliently press the wheels carried thereby against their associated rails.

6. A drafting instrument according to claim 2, wherein one of said walls of the straight edge is additiona-llly provided with a central longitudinal slot, said pivot stud on the vertical liner being formed with a slot in the face of its free end, a disc positioned under said slotted Wall of the straight edge and having a pin at one side extending through the wall slot and an oppositely directed rib at the other side, said rib being seated in the slot of said pivot stud, and a manually movable knob secured to said pin outside of said straight edge for manipulating the vertical liner.

References Cited in the file of this patent UNITED STATES PATENTS 858,913 Sauer July 2, 1907 2,102,636 McDonald Dec. 21, 1937 2,918,726 Kalbunde Dec. 29, 1959 2,954,609 Goertz Oct. 4, 1960 FOREIGN PATENTS 1,169,465 France Sept. 8, 1958 

2. A DRAFTING INSTRUMENT COMPRISING A MOUNTING PLATE FOR FIXED SECUREMENT TO AN EDGE OF A DRAFTING TABLE, SAID MOUNTING PLATE HAVING A PAIR OF LONGITUDINAL INWARDLY BENT FLANGES FORMING PARALLEL RAILS, A FLAT PLATE CARRIAGE HAVING DISC WHEELS AT ITS CORNERS PARALLEL TO THE PLANE OF THE CARRIAGE AND EACH WHEEL HAVING A PERIPHERAL GROOVE ENGAGED IN ONE OF SAID RAILS, A STRAIGHT EDGE PERPENDICULAR TO THE RAILS OF SAID MOUNTING PLATE, SAID STRAIGHT EDGE BEING FORMED OF A FLAT SHEET FOLDED TO PROVIDE CLOSELY SPACED PARALLEL WALLS OPEN AT ONE SIDE, MEANS FOR SECURING SAID STRAIGHT EDGE TO SAID CARRIAGE ON THE MOUNTING PLATE FOR MOVEMENT ALONG THE MOUNTING PLATE RAILS, A VERTICAL LINER HAVING ONE END POSTIONED BETWEEN THE PARALLEL WALLS OF SAID STRAIGHT EDGE, A PIVOT STUD AT SAID END OF THE VERTICAL LINER AND A PAIR OF DETENTS SPACED 90* APART IN AN ARCH ABOUT SAID PIVOT STUD, A SECOND FLAT PLATE CARRIAGE HAVING A CENTRAL OPENING RECEIVING SAID PIVOT STUD AND POSITIONED WITHIN THE STRAIGHT EDGE BETWEEN THE PARALLEL SIDES THEREOF, SAID SECOND CARRIAGE HAVING SEMICIRCULAR SLOT ENDING IN BENT TERMINAL FLANGES FOR WEDGING ENGAGEMENT WITH SAID PAIR OF DETENDS, DISC WHEELS AT THE CORNERS OF SAID SECOND CARRIAGE HAVING PERIPHERAL GROOVES, ONE OF SAID PARALLEL WALLS OF THE STRAIGHT EDGE HAVING A PAIR OF LONGITUDINAL PARALLEL RAILS FORMED BY FLANGES AND BENT INWARDLY TO EXTEND INTO THE SPACE BETWEEN THE WALLS OF THE STRAIGHT EDGE, SAID PERIPHERAL GROOVES OF THE WHEELS OF THE SECOND CARRIAGE ENGAGING THE STRAIGHT EDGE RAILS, AND MEANS FOR SECCURING SAID PIVOT STUD OF THE VERTICAL LINER ASSEMBLED IN ROTATIONAL ENGAGEMENT WITH SAID SECOND CARRIAGE WHEREBY SAID LINER IS MOVABLE FROM A COVERED POSITION SEATED BETWEEN THE WALLS OF AND WITHIN SAID STRAIGHT EDGE TO AN EXTENDED WORK POSITION PERPENDICULAR THERETO, THE MOVEMENTS BETWEEN SAID POSITIONS BEING LIMITED BY ENGAGEMENT OF SAID DETENTS ON THE LINER WITH SAID TERMINAL FLANGES ON SECOND CARRIAGE. 